This paper deals with the modelling of substrate microbial growth process. For the successful applications and overall model validation in microbial growth pocesses, a new substrate inhibition model-modified been developed. Performances are compared on the basis of different experimental data in the literature and, of parameter sensitivity analysis. Finally, the parameter sensitivity analysis emphasizes that the modified Handane model has a very simple but flexible enough model structure for representing the microbial growth kinetics with limited number of parameters.